Hierarchical framework for coordinate optimization of train timetable and electric motor train unit circulation plan

Abstract

To meet the increasing demand for improving railway service quality while using the precious mobile resources reasonably and economically, this research proposes a hierarchical approach that integrates the model for constructing an efficient electric motor train unit circulation plan into the model for optimized timetable design without predefining timetable details. A simulated annealing algorithm for solving the timetabling (main) model is designed, in which the neighborhood system is pretreated. A special tree construction–based branch-and-bound algorithm is improved for solving the electric motor train unit circulation planning (sub)model. The results of the numerical experiment verify the effectiveness of the proposed method. Specifically, compared to the randomly generated initial solution, the optimal solution obtained by the proposed methods reduces the total travel time by 686 min and reduces the number of electric motor train units by 5. The number of electric motor train units needed by the proposed method is on average at least two less than the method that handles the problem in a sequential way. Railway operators can implement this approach for balancing the efficiency of timetable and the quality of electric motor train unit circulation plan within a reasonable computation time when scheduling trains in railways.